matplotlib · scottshambaugh · Mar 14, 2026 · Mar 12, 2026
diff --git a/lib/matplotlib/mpl-data/stylelib/classic.mplstyle b/lib/matplotlib/mpl-data/stylelib/classic.mplstyle
@@ -213,8 +213,9 @@ axes.prop_cycle    : cycler('color', 'bgrcmyk')
                                            # single letter, long name, or
                                            # web-style hex
 axes.autolimit_mode : round_numbers
-axes.xmargin        : 0  # x margin.  See `axes.Axes.margins`
-axes.ymargin        : 0  # y margin See `axes.Axes.margins`
+axes.xmargin        : 0  # x margin. See `axes.Axes.margins`
+axes.ymargin        : 0  # y margin. See `axes.Axes.margins`
+axes.zmargin        : 0  # z margin. See `axes.Axes.margins`
 axes.spines.bottom  : True
 axes.spines.left    : True
 axes.spines.right   : True

diff --git a/lib/mpl_toolkits/mplot3d/axes3d.py b/lib/mpl_toolkits/mplot3d/axes3d.py
@@ -157,11 +157,10 @@ def __init__(
 
         self.xy_viewLim = Bbox.unit()
         self.zz_viewLim = Bbox.unit()
-        xymargin = 0.05 * 10/11  # match mpl3.8 appearance
-        self.xy_dataLim = Bbox([[xymargin, xymargin],
-                                [1 - xymargin, 1 - xymargin]])
-        # z-limits are encoded in the x-component of the Bbox, y is un-used
-        self.zz_dataLim = Bbox.unit()
+        self._xmargin = mpl.rcParams['axes.xmargin']
+        self._ymargin = mpl.rcParams['axes.ymargin']
+        self._zmargin = mpl.rcParams['axes.zmargin']
+        self._init_dataLims()
 
         # inhibit autoscale_view until the axes are defined
         # they can't be defined until Axes.__init__ has been called
@@ -602,6 +601,25 @@ def margins(self, *margins, x=None, y=None, z=None, tight=True):
             scalez=(z is not None)
         )
 
+    def _init_dataLims(self):
+        """Reset dataLim bboxes for empty-plot defaults.
+
+        The per-axis padding ensures that the margin expansion in autoscale_view
+        cancels out exactly, landing on [0, 1] for empty plots.
+        """
+        def pad(margin):
+            # Note margin is validated to be > -0.5 in rcParams and set_x/y/zmargin
+            return margin / (1 + 2 * margin) if margin > 0 else 0
+
+        xpad = pad(self._xmargin)
+        ypad = pad(self._ymargin)
+        zpad = pad(self._zmargin)
+        self.xy_dataLim = Bbox([[xpad, ypad],
+                                [1 - xpad, 1 - ypad]])
+        # z-limits are encoded in the x-component of the Bbox, y is un-used
+        self.zz_dataLim = Bbox([[zpad, 0],
+                                [1 - zpad, 1]])
+
     def autoscale(self, enable=True, axis='both', tight=None):
         """
         Convenience method for simple axis view autoscaling.
@@ -1142,18 +1160,6 @@ def _set_axis_scale(self, axis, value, **kwargs):
         **kwargs
             Forwarded to scale constructor.
         """
-        # For non-linear scales on the z-axis, switch from the [0, 1] +
-        # margin=0 representation to the same xymargin + margin=0.05
-        # representation that x/y use.  Both produce identical linear limits,
-        # but only the xymargin form has valid positive lower bounds for log
-        # etc.  This must happen before _set_axes_scale because that triggers
-        # autoscale_view internally.
-        if (axis is self.zaxis and value != 'linear'
-                and np.array_equal(self.zz_dataLim.get_points(), [[0, 0], [1, 1]])):
-            xymargin = 0.05 * 10/11
-            self.zz_dataLim = Bbox([[xymargin, xymargin],
-                                    [1 - xymargin, 1 - xymargin]])
-            self._zmargin = self._xmargin
         axis._set_axes_scale(value, **kwargs)
 
     def set_xscale(self, value, **kwargs):
@@ -1556,16 +1562,8 @@ def shareview(self, other):
     def clear(self):
         # docstring inherited.
         super().clear()
-        if self._focal_length == np.inf:
-            self._zmargin = mpl.rcParams['axes.zmargin']
-        else:
-            self._zmargin = 0.
-
-        xymargin = 0.05 * 10/11  # match mpl3.8 appearance
-        self.xy_dataLim = Bbox([[xymargin, xymargin],
-                                [1 - xymargin, 1 - xymargin]])
-        # z-limits are encoded in the x-component of the Bbox, y is un-used
-        self.zz_dataLim = Bbox.unit()
+        self._zmargin = mpl.rcParams['axes.zmargin']  # x, y are set in super().clear()
+        self._init_dataLims()
         self._view_margin = 1/48  # default value to match mpl3.8
         self.autoscale_view()
 
@@ -3235,9 +3233,6 @@ def scatter(self, xs, ys, zs=0, zdir='z', s=20, c=None, depthshade=None,
             depthshade_minalpha=depthshade_minalpha,
             axlim_clip=axlim_clip,
         )
-        if self._zmargin < 0.05 and xs.size > 0:
-            self.set_zmargin(0.05)
-
         self.auto_scale_xyz(xs, ys, zs, had_data)
 
         return patches

diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/aspects.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/aspects.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/aspects_adjust_box.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/aspects_adjust_box.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d_notshaded.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d_notshaded.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d_shaded.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/bar3d_shaded.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/computed_zorder.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/computed_zorder.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/errorbar3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/errorbar3d.png
diff --git a/...pl_toolkits/mplot3d/tests/baseline_images/test_axes3d/errorbar3d_errorevery.png b/...pl_toolkits/mplot3d/tests/baseline_images/test_axes3d/errorbar3d_errorevery.png
diff --git a/...mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/fill_between_polygon.png b/...mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/fill_between_polygon.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/fill_between_quad.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/fill_between_quad.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/lines3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/lines3d.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/plot_3d_from_2d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/plot_3d_from_2d.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/quiver3d_colorcoded.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/quiver3d_colorcoded.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/quiver3d_masked.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/quiver3d_masked.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/scale3d_artists_log.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/scale3d_artists_log.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/stem3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/stem3d.png
diff --git a/...ot3d/tests/baseline_images/test_axes3d/surface3d_label_offset_tick_position.png b/...ot3d/tests/baseline_images/test_axes3d/surface3d_label_offset_tick_position.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_masked.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_masked.png
diff --git a/...toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_masked_strides.png b/...toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_masked_strides.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_zsort_inf.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/surface3d_zsort_inf.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/tricontour.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/tricontour.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/trisurf3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/trisurf3d.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/trisurf3d_shaded.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/trisurf3d_shaded.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-alpha.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-alpha.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-edge-style.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-edge-style.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-named-colors.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-named-colors.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-rgb-data.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-rgb-data.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-simple.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-simple.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-xyz.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/voxels-xyz.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3d.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3d.png
diff --git a/...pl_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dasymmetric.png b/...pl_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dasymmetric.png
diff --git a/...l_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dzerocstride.png b/...l_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dzerocstride.png
diff --git a/...l_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dzerorstride.png b/...l_toolkits/mplot3d/tests/baseline_images/test_axes3d/wireframe3dzerorstride.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_legend3d/legend_bar.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_legend3d/legend_bar.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_legend3d/legend_plot.png b/lib/mpl_toolkits/mplot3d/tests/baseline_images/test_legend3d/legend_plot.png
diff --git a/lib/mpl_toolkits/mplot3d/tests/test_axes3d.py b/lib/mpl_toolkits/mplot3d/tests/test_axes3d.py
@@ -161,7 +161,7 @@ def test_bar3d_colors():
         ax.bar3d(xs, ys, zs, 1, 1, 1, color=c)
 
 
-@mpl3d_image_comparison(['bar3d_shaded.png'], style='mpl20')
+@mpl3d_image_comparison(['bar3d_shaded.png'], tol=0.035, style='mpl20')
 def test_bar3d_shaded():
     x = np.arange(4)
     y = np.arange(5)
@@ -299,7 +299,6 @@ def test_contourf3d_extend(fig_test, fig_ref, extend, levels):
 
 @mpl3d_image_comparison(['tricontour.png'], tol=0.02, style='mpl20')
 def test_tricontour():
-    plt.rcParams['axes3d.automargin'] = True  # Remove when image is regenerated
     fig = plt.figure()
 
     np.random.seed(19680801)
@@ -587,7 +586,7 @@ def test_marker_draw_order_view_rotated(fig_test, fig_ref):
     ax.view_init(elev=0, azim=azim - 180, roll=0)  # view rotated by 180 deg
 
 
-@mpl3d_image_comparison(['plot_3d_from_2d.png'], tol=0.019, style='mpl20')
+@mpl3d_image_comparison(['plot_3d_from_2d.png'], tol=0.03, style='mpl20')
 def test_plot_3d_from_2d():
     fig = plt.figure()
     ax = fig.add_subplot(projection='3d')
@@ -1509,7 +1508,7 @@ def test_alpha(self):
             assert isinstance(poly, art3d.Poly3DCollection)
 
     @mpl3d_image_comparison(['voxels-xyz.png'], remove_text=False, style='mpl20',
-                            tol=0.002 if sys.platform == 'win32' else 0)
+                            tol=0 if platform.machine() == 'x86_64' else 0.008)
     def test_xyz(self):
         fig, ax = plt.subplots(subplot_kw={"projection": "3d"})
 
@@ -1739,7 +1738,7 @@ def test_errorbar3d():
 
 
 @image_comparison(['stem3d.png'], style='mpl20',
-                  tol=0 if platform.machine() == 'x86_64' else 0.008)
+                  tol=0 if platform.machine() == 'x86_64' else 0.01)
 def test_stem3d():
     fig, axs = plt.subplots(2, 3, figsize=(8, 6),
                             constrained_layout=True,
@@ -2209,7 +2208,6 @@ def test_subfigure_simple():
 
 @image_comparison(['computed_zorder.png'], remove_text=True, style='mpl20')
 def test_computed_zorder():
-    plt.rcParams['axes3d.automargin'] = True  # Remove when image is regenerated
     fig = plt.figure()
     ax1 = fig.add_subplot(221, projection='3d')
     ax2 = fig.add_subplot(222, projection='3d')
@@ -2664,7 +2662,6 @@ def test_scatter_masked_color():
 
 @mpl3d_image_comparison(['surface3d_zsort_inf.png'], style='mpl20')
 def test_surface3d_zsort_inf():
-    plt.rcParams['axes3d.automargin'] = True  # Remove when image is regenerated
     fig = plt.figure()
     ax = fig.add_subplot(projection='3d')
 
@@ -2994,6 +2991,72 @@ def test_scale3d_default_limits(scale, expected_lims):
         np.testing.assert_allclose(get_lim(), expected_lims)
 
 
+@pytest.mark.parametrize("scale, expected_lims", [
+    ("linear", (0.041666666666666664, 0.9583333333333334)),
+    ("log", (0.08519612008506527, 1.056386134839687)),
+    ("symlog", (0.04166666666666668, 0.9583333333333334)),
+    ("logit", (0.0746298566901612, 0.9253701433098389)),
+    ("asinh", (0.04815235510959675, 0.9707897299792895)),
+])
+@mpl.style.context("default")
+def test_scale3d_automargin_limits(scale, expected_lims):
+    """Axis limits with data and automargin should be correct for each scale."""
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='3d')
+    ax.set_xscale(scale)
+    ax.set_yscale(scale)
+    ax.set_zscale(scale)
+    ax.plot([0.1, 0.9], [0.1, 0.9], [0.1, 0.9])
+    fig.canvas.draw()
+
+    for get_lim in (ax.get_xlim, ax.get_ylim, ax.get_zlim):
+        np.testing.assert_allclose(get_lim(), expected_lims)
+
+
+@pytest.mark.parametrize("scale, expected_lims", [
+    ("linear", (0.08333333333333334, 0.9166666666666667)),
+    ("log", (0.09552563816905349, 0.9421554435545909)),
+    ("symlog", (0.08333333333333334, 0.9166666666666667)),
+    ("logit", (0.09205683697189532, 0.9079431630281046)),
+    ("asinh", (0.08516517850312533, 0.9199719582595468)),
+])
+@mpl.style.context("default")
+def test_scale3d_zero_margin_limits(scale, expected_lims):
+    """Axis limits with data and zero margins should be correct for each scale.
+
+    Limits are not exactly (0.1, 0.9) because view_margin still applies.
+    """
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='3d')
+    ax.set_xscale(scale)
+    ax.set_yscale(scale)
+    ax.set_zscale(scale)
+    ax.margins(0)
+    ax.plot([0.1, 0.9], [0.1, 0.9], [0.1, 0.9])
+    fig.canvas.draw()
+
+    for get_lim in (ax.get_xlim, ax.get_ylim, ax.get_zlim):
+        np.testing.assert_allclose(get_lim(), expected_lims)
+
+
+@pytest.mark.parametrize("scale", ["linear", "log", "symlog", "logit", "asinh"])
+@mpl.style.context("default")
+def test_scale3d_explicit_limits(scale):
+    """Explicitly set limits should be honored exactly for each scale."""
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='3d')
+    ax.set_xscale(scale)
+    ax.set_yscale(scale)
+    ax.set_zscale(scale)
+    ax.set_xlim(0.1, 0.9)
+    ax.set_ylim(0.1, 0.9)
+    ax.set_zlim(0.1, 0.9)
+    fig.canvas.draw()
+
+    for get_lim in (ax.get_xlim, ax.get_ylim, ax.get_zlim):
+        np.testing.assert_allclose(get_lim(), (0.1, 0.9))
+
+
 @check_figures_equal()
 @pytest.mark.filterwarnings("ignore:Data has no positive values")
 def test_scale3d_all_clipped(fig_test, fig_ref):